FTDI struggles to transfer above 38400baud?

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Bambo
Posts: 75
Joined: Wed Jan 15, 2020 8:36 pm

FTDI struggles to transfer above 38400baud?

Post by Bambo »

Hi, just trying to output a sine wave to a serial montior via an USART-USB FTDI device. When i put the baud rate higher than 38400 baud, the output becomes laggy? Does anyone know why this is?
Beuzekom
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Joined: Thu Jul 30, 2020 1:32 pm
Answers: 1

Re: FTDI struggles to transfer above 38400baud?

Post by Beuzekom »

Are you using HardwareSerial?
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fpiSTM
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Re: FTDI struggles to transfer above 38400baud?

Post by fpiSTM »

Which board? which board? Sketch? ...
mrburnette
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Joined: Thu Dec 19, 2019 1:23 am
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Re: FTDI struggles to transfer above 38400baud?

Post by mrburnette »

Bambo wrote: Wed Feb 10, 2021 11:53 am Hi, just trying to output a sine wave to a serial montior via an USART-USB FTDI device. When i put the baud rate higher than 38400 baud, the output becomes laggy? Does anyone know why this is?
Oh, my... it could be your
- USB cable
- faux chip
- USB host driver
- Host OS
- sine wave (software?) code

... and more.

Put things in prospective and loop-back the "ftdi" device, do some round-robbing tests on the host PC.
Then, try another PC and another cable.

You may need to buy a quality module + cable combination which I often recommend:
https://www.adafruit.com/product/954
ag123
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Re: FTDI struggles to transfer above 38400baud?

Post by ag123 »

uart is just that async, but throughput can go pretty high. for usb-serial i've occasionally seen throughput > 1 mbps, but it does not necessarily mean always 1 mbps constant. and usb does polling, bandwidth is shared by all the devices that the host need to poll
https://www.beyondlogic.org/usbnutshell/usb1.shtml
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